Sourcing Power From a Battery or AC-DC Converter of a Power Storage Adapter

ABSTRACT

An external power storage adapter (PSA) may supply electrical power to a portable information handling system or other power consuming device. The power storage adapter may include an AC-DC converter, a battery, and intelligent power management functionality. A PSA controller may determine whether electrical power supplied by the power storage adapter should be sourced from the AC-DC converter or from the battery based on various operating parameters of the power storage adapter, such the temperature of the power storage adapter, the state of charge of the battery, the amount of electrical power being supplied by the AC-DC converter, or the amount of time that the AC-DC converter has been supplying electrical power. The power storage adapter may output power to a port of the portable information handling system, such as a USB Type-C port, over a variable power bus.

BACKGROUND Field of the Disclosure

This disclosure relates generally to information handling systems and,more particularly, to systems and methods for selectively sourcing powerfrom a battery or AC-DC converter of a high efficiency power storageadapter.

Description of the Related Art

As the value and use of information continues to increase, individualsand businesses seek additional ways to process and store information.One option available to users is information handling systems. Aninformation handling system generally processes, compiles, stores, andcommunicates information or data for business, personal, or otherpurposes thereby allowing users to take advantage of the value of theinformation. Because technology and information handling needs andrequirements vary between different users or applications, informationhandling systems may also vary regarding what information is handled,how the information is handled, how much information is processed,stored, or communicated, and how quickly and efficiently the informationmay be processed, stored, or communicated. The variations in informationhandling systems allow for information handling systems to be general orconfigured for a specific user or specific use such as financialtransaction processing, airline reservations, enterprise data storage,or global communications. In addition, information handling systems mayinclude a variety of hardware and software components that may beconfigured to process, store, and communicate information and mayinclude one or more computer systems, data storage systems, andnetworking systems.

Examples of information handling systems include portable devices suchas notebook computers, media players, personal data assistants, digitalcameras, cellular phones, cordless phones, smart phones, tabletcomputers, and 2-in-1 tablet-laptop combination computers. A portabledevice may generally be any device that a user may carry for handhelduse and that includes a processor. Typically, portable devices arepowered using a rechargeable battery and include a display device.

SUMMARY

In one aspect, a disclosed power storage adapter (PSA) includes a portfor coupling the power storage adapter to a variable power bus, abattery, an AC-DC converter, power distribution circuitry to supplyelectrical power from the power storage adapter at a plurality of outputvoltage levels, and a PSA controller. The PSA controller may includecircuitry to, when the AC-DC converter is coupled to AC line power and apower consuming device is coupled to the power storage adapter over thevariable power bus through the port, and responsive to a request for thepower storage adapter to supply electrical power to the power consumingdevice at a particular voltage, determine, based on an operatingparameter of the power storage adapter, one of an output of the AC-DCconverter or an output of the battery as a selected source for supplyingelectrical power to the power consuming device, and cause the powerdistribution circuitry to supply electrical power from the selectedsource to the power consuming device over the variable power bus at theparticular voltage. The particular voltage is one of the plurality ofoutput voltage levels.

In any of the disclosed embodiments, the power consuming device may bean information handling system comprising an internal battery.

In any of the disclosed embodiments, the power storage adapter mayfurther include a sensor, and the operating parameter may be dependenton a measurement value obtained by the sensor.

In any of the disclosed embodiments, to determine the selected source,the PSA controller circuitry may further be to determine that a state ofcharge of the battery is greater than a threshold state of charge forsupplying electrical power to the power consuming device at theparticular voltage, and responsive to determining that the state ofcharge of the battery is greater than the threshold state of charge, todetermine that the selected source for supplying electrical power to thepower consuming device is to be changed from an output of the AC-DCconverter to an output of the battery, dependent on at least one of adetermination that a temperature of the power storage adapter is greaterthan a threshold temperature for sourcing electrical power from theAC-DC converter, a percentage of a maximum power supply capacity of theAC-DC converter at which the AC-DC converter is currently operating, andan amount of time that the AC-DC converter has been operating to supplyelectrical power to the power consuming device.

In any of the disclosed embodiments, to determine the selected source,the PSA controller circuitry may further be to determine that theselected source for supplying electrical power to the power consumingdevice is to be changed from an output of the battery to an output ofthe AC-DC converter, dependent on at least one of a determination that astate of charge of the battery is less than or equal to a thresholdstate of charge for supplying electrical power to the power consumingdevice at the particular voltage, and a determination that a temperatureof the power storage adapter is less than or equal to a thresholdtemperature for sourcing electrical power from the AC-DC converter.

In any of the disclosed embodiments, the PSA controller may utilize auniversal serial bus (USB) power delivery protocol layer forcommunicating with and supplying electrical power to the power consumingdevice over the variable power bus, the port may a USB Type-C port, andthe PSA controller may further include circuitry to establish a powerdelivery contract to supply electrical power to the power consumingdevice at the particular voltage.

In any of the disclosed embodiments, the AC-DC converter may be adefault source for supplying electrical power to the power consumingdevice when the AC-DC converter is coupled to AC line power and thepower consuming device is coupled to the power storage adapter over thevariable power bus through the port, and to determine the selectedsource, the PSA controller circuitry may further be to override thedefault source to determine that an output of the battery is theselected source for supplying electrical power to the power consumingdevice.

In any of the disclosed embodiments, the PSA controller circuitry mayinclude a processor, and a memory storing program instructions that whenexecuted by the processor cause the processor to perform the determiningof the selected source, and generating one or more control signals tocause the power distribution circuitry to supply electrical power fromthe selected source to the power consuming device over the variablepower bus at the particular voltage.

In any of the disclosed embodiments, the power storage adapter mayfurther include a DC-DC converter comprising circuitry to boost aninitial output voltage of the battery to the particular voltage togenerate a boosted output voltage at which electrical power is suppliedto the power consuming device over the variable power bus.

In another aspect, a disclosed method is for supplying power to a powerconsuming device, such as a portable information handling system. In atleast some embodiments, the method may include, when an AC-DC converterof a power storage adapter (PSA) is coupled to AC line power and a powerconsuming device is coupled to the power storage adapter over a variablepower bus, and responsive to receiving a request for the power storageadapter to supply electrical power to the power consuming device at aparticular voltage, determining, based on an operating parameter of thepower storage adapter, one of an output of the AC-DC converter or anoutput of a battery within the power storage adapter as a selectedsource for supplying electrical power to the power consuming device, andcausing power distribution circuitry within the power storage adapter tosupply electrical power from the selected source to the power consumingdevice over the variable power bus at the particular voltage. Theparticular voltage is one of a plurality of output voltage levels atwhich electrical power is supplied by the power distribution circuitrywithin the power storage adapter.

In any of the disclosed embodiments, the power consuming device may bean information handling system comprising an internal battery.

In any of the disclosed embodiments, the operating parameter may bedependent on a measurement value obtained by a sensor within the powerstorage adapter.

In any of the disclosed embodiments, determining the selected source mayinclude determining that a state of charge of the battery is greaterthan a threshold state of charge for supplying electrical power to thepower consuming device at the particular voltage, and responsive todetermining that the state of charge of the battery is greater than thethreshold state of charge, determining that the selected source forsupplying electrical power to the power consuming device is to bechanged from an output of the AC-DC converter to an output of thebattery, dependent on at least one of a determination that a temperatureof the power storage adapter is greater than a threshold temperature forsourcing electrical power from the AC-DC converter, a percentage of amaximum power supply capacity of the AC-DC converter at which the AC-DCconverter is currently operating, and an amount of time that the AC-DCconverter has been operating to supply electrical power to the powerconsuming device.

In any of the disclosed embodiments, determining the selected source mayinclude determining that the selected source for supplying electricalpower to the power consuming device is to be changed from an output ofthe battery to an output of the AC-DC converter, dependent on at leastone of a determination that a state of charge of the battery is lessthan or equal to a threshold state of charge for supplying electricalpower to the power consuming device at the particular voltage, and adetermination that a temperature of the power storage adapter is lessthan or equal to a threshold temperature for sourcing electrical powerfrom the AC-DC converter.

In any of the disclosed embodiments, the power storage adapter utilizesa universal serial bus (USB) power delivery protocol layer forcommunicating with and supplying electrical power to the power consumingdevice over the variable power bus through a USB Type-C port of thepower storage adapter, and the method may further include establishing apower delivery contract to supply electrical power to the powerconsuming device at the particular voltage.

In any of the disclosed embodiments, the AC-DC converter may be adefault source for supplying electrical power to the power consumingdevice when the AC-DC converter is coupled to AC line power and thepower consuming device is coupled to the power storage adapter over thevariable power bus through the port, and determining the selected sourcemay include overriding the default source to determine that an output ofthe battery is the selected source for supplying electrical power to thepower consuming device.

In any of the disclosed embodiments, causing power distributioncircuitry within the power storage adapter to supply electrical powerfrom the selected source to the power consuming device over the variablepower bus at the particular voltage may include boosting an initialoutput voltage of the battery to the particular voltage to generate aboosted output voltage at which electrical power is supplied to thepower consuming device over the variable power bus.

In a further aspect, a disclosed system includes an information handlingsystem including an internal port for coupling the information handlingsystem to a variable power bus, and a power storage adapter (PSA). Thepower storage adapter may include a PSA port for coupling the powerstorage adapter to the information handling system over the variablepower bus, a battery, an AC-DC converter, power distribution circuitryto supply electrical power from the power storage adapter at a pluralityof output voltage levels, and a PSA controller. The PSA controller mayinclude circuitry to, when the AC-DC converter is coupled to AC linepower and the information handling system is coupled to the powerstorage adapter over the variable power bus through the port, andresponsive to a request for the power storage adapter to supplyelectrical power to the information handling system at a particularvoltage, determine, based on an operating parameter of the power storageadapter, one of an output of the AC-DC converter or an output of thebattery as a selected source for supplying electrical power to theinformation handling system, and cause the power distribution circuitryto supply electrical power from the selected source to the informationhandling system over the variable power bus at the particular voltage.The particular voltage may be one of the plurality of output voltagelevels.

In any of the disclosed embodiments, to determine the selected source,the PSA controller circuitry may further be to determine that a state ofcharge of the battery is greater than a threshold state of charge forsupplying electrical power to the information handling system at theparticular voltage, and responsive to determining that the state ofcharge of the battery is greater than the threshold state of charge, todetermine that the selected source for supplying electrical power to theinformation handling system is to be changed from an output of the AC-DCconverter to an output of the battery, dependent on at least one of adetermination that a temperature of the power storage adapter is greaterthan a threshold temperature for sourcing electrical power from theAC-DC converter, a percentage of a maximum power supply capacity of theAC-DC converter at which the AC-DC converter is currently operating, andan amount of time that the AC-DC converter has been operating to supplyelectrical power to the information handling system.

In any of the disclosed embodiments, to determine the selected source,the PSA controller circuitry may be further to determine that theselected source for supplying electrical power to the informationhandling system is to be changed from an output of the battery to anoutput of the AC-DC converter, dependent on at least one of adetermination that a state of charge of the battery is less than orequal to a threshold state of charge for supplying electrical power tothe information handling system at the particular voltage, and adetermination that a temperature of the power storage adapter is lessthan or equal to a threshold temperature for sourcing electrical powerfrom the AC-DC converter.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and itsfeatures and advantages, reference is now made to the followingdescription, taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a block diagram of selected elements of an embodiment of aportable information handling system;

FIG. 2 is a block diagram of selected elements of an embodiment of aportable information handling system with an external power storageadapter;

FIGS. 3A and 3B are a block diagrams of selected elements of embodimentsof a power storage adapter;

FIG. 4 is a plot showing selected elements of a charging curve for aninformation handling system battery;

FIG. 5 is a state diagram for an embodiment of a power storage adaptercontroller;

FIG. 6 is a flow chart of selected elements of an embodiment of a methodfor sourcing power from a battery or AC-DC converter of a power storageadapter; and

FIG. 7 is a flow chart of selected elements of an embodiment of a methodfor determining a selected source of power in a power storage adapter.

DESCRIPTION OF PARTICULAR EMBODIMENT(S)

In the following description, details are set forth by way of example tofacilitate discussion of the disclosed subject matter. It should beapparent to a person of ordinary skill in the field, however, that thedisclosed embodiments are exemplary and not exhaustive of all possibleembodiments.

As used herein, a hyphenated form of a reference numeral refers to aspecific instance of an element and the un-hyphenated form of thereference numeral refers to the collective or generic element. Thus, forexample, widget “72-1” refers to an instance of a widget class, whichmay be referred to collectively as widgets “72” and any one of which maybe referred to generically as a widget “72”.

For the purposes of this disclosure, an information handling system mayinclude an instrumentality or aggregate of instrumentalities operable tocompute, classify, process, transmit, receive, retrieve, originate,switch, store, display, manifest, detect, record, reproduce, handle, orutilize various forms of information, intelligence, or data forbusiness, scientific, control, entertainment, or other purposes. Forexample, an information handling system may be a personal computer, aPDA, a consumer electronic device, a network storage device, or anothersuitable device and may vary in size, shape, performance, functionality,and price. The information handling system may include memory, one ormore processing resources such as a central processing unit (CPU) orhardware or software control logic. Additional components or theinformation handling system may include one or more storage devices, oneor more communications ports for communicating with external devices aswell as various input and output (I/O) devices, such as a keyboard, amouse, and a video display. The information handling system may alsoinclude one or more buses operable to transmit communication between thevarious hardware components.

For the purposes of this disclosure, computer-readable media may includean instrumentality or aggregation of instrumentalities that may retaindata and instructions for a period of time. Computer-readable media mayinclude, without limitation, storage media such as a direct accessstorage device (e.g., a hard disk drive or floppy disk), a sequentialaccess storage device (e.g., a tape disk drive), compact disk, CD-ROM,DVD, random access memory (RAM), read-only memory (ROM), electricallyerasable programmable read-only memory (EEPROM), and flash memory (SSD);as well as communications media such wires, optical fibers, microwaves,radio waves, and other electromagnetic or optical carriers; or anycombination of the foregoing.

Particular embodiments are best understood by reference to FIGS. 1, 2,3A, 3B, 4, 5, and 6 wherein like numbers are used to indicate like andcorresponding parts.

Turning now to the drawings, FIG. 1 illustrates a block diagramdepicting selected elements of an embodiment of portable informationhandling system 100. It is noted that FIG. 1 is not drawn to scale butis a schematic illustration. In various embodiments, portableinformation handling system 100 may represent different types ofportable devices. A portable device may generally be any device that auser may carry for handheld use and that includes a processor.Typically, portable devices are powered using a rechargeable battery.Examples of portable information handling system 100 may include laptopcomputers, notebook computers, netbook computers, tablet computers, and2-in-1 tablet laptop combination computers, among others. In someinstances, portable information handling system 100 may representcertain personal mobile devices, and may further include examples suchas media players, personal data assistants, digital cameras, cellularphones, cordless phones, smart phones, and other cellular networkdevices.

As shown in FIG. 1, components of information handling system 100 mayinclude, but are not limited to, a processor subsystem 120, which maycomprise one or more processors, and a system bus 121 thatcommunicatively couples various system components to processor subsystem120 including, for example, a memory 130, an I/O subsystem 140, localstorage resource 150, and a network interface 160. Also shown withininformation handling system 100 is embedded controller 180 and aninternal battery management unit (BMU) 170-1 that manages an internalbattery 171. Furthermore, information handling system 100 is shownremovably coupled to a power storage adapter 172 that incorporatesvarious high efficiency features for use with portable informationhandling system 100, as disclosed herein. As shown, power storageadapter 172 may be an external device to portable information handlingsystem 100 and may be coupled to portable information handling system100 using a variable power bus 142, for example, using an appropriateconnector, as described in further detail below.

As depicted in FIG. 1, processor subsystem 120 may comprise a system,device, or apparatus operable to interpret and execute programinstructions and process data, and may include a microprocessor,microcontroller, digital signal processor (DSP), application specificintegrated circuit (ASIC), or another digital or analog circuitryconfigured to interpret and execute program instructions and processdata. In some embodiments, processor subsystem 120 may interpret andexecute program instructions and process data stored locally (e.g., inmemory 130). In the same or alternative embodiments, processor subsystem120 may interpret and execute program instructions and process datastored remotely (e.g., in a network storage resource).

In FIG. 1, system bus 121 may represent a variety of suitable types ofbus structures, e.g., a memory bus, a peripheral bus, or a local bususing various bus architectures in selected embodiments. For example,such architectures may include, but are not limited to, Micro ChannelArchitecture (MCA) bus, Industry Standard Architecture (ISA) bus,Enhanced ISA (EISA) bus, Peripheral Component Interconnect (PCI) bus,PCI-Express bus, HyperTransport (HT) bus, and Video ElectronicsStandards Association (VESA) local bus.

Also in FIG. 1, memory 130 may comprise a system, device, or apparatusoperable to retain and retrieve program instructions and data for aperiod of time (e.g., computer-readable media). Memory 130 may compriserandom access memory (RAM), electrically erasable programmable read-onlymemory (EEPROM), a PCMCIA card, flash memory, magnetic storage,opto-magnetic storage or a suitable selection or array of volatile ornon-volatile memory that retains data after power is removed. In FIG. 1,memory 130 is shown including an operating system (OS) 132, which mayrepresent an execution environment for portable information handlingsystem 100. Operating system 132 may be UNIX or be based on UNIX (e.g.,a LINUX variant), one of a number of variants of Microsoft Windows®operating systems, a mobile device operating system (e.g., GoogleAndroid™ platform, Apple® iOS, among others), an Apple® MacOS operatingsystem, an embedded operating system, a gaming operating system, oranother suitable operating system.

In FIG. 1, local storage resource 150 may comprise computer-readablemedia (e.g., hard disk drive, floppy disk drive, CD-ROM, and other typeof rotating storage media, flash memory, EEPROM, or another type ofsolid state storage media) and may be generally operable to storeinstructions and data, and to permit access to stored instructions anddata on demand.

In FIG. 1, network interface 160 may be a suitable system, apparatus, ordevice operable to serve as an interface between information handlingsystem 100 and a network (not shown). Network interface 160 may enableinformation handling system 100 to communicate over the network using asuitable transmission protocol or standard. In some embodiments, networkinterface 160 may be communicatively coupled via the network to anetwork storage resource (not shown). The network coupled to networkinterface 160 may be implemented as, or may be a part of, a storage areanetwork (SAN), personal area network (PAN), local area network (LAN), ametropolitan area network (MAN), a wide area network (WAN), a wirelesslocal area network (WLAN), a virtual private network (VPN), an intranet,the Internet or another appropriate architecture or system thatfacilitates the communication of signals, data and messages (generallyreferred to as data). The network coupled to network interface 160 maytransmit data using a desired storage or communication protocol,including, but not limited to, Fibre Channel, Frame Relay, AsynchronousTransfer Mode (ATM), Internet protocol (IP), other packet-basedprotocol, small computer system interface (SCSI), Internet SCSI (iSCSI),Serial Attached SCSI (SAS) or another transport that operates with theSCSI protocol, advanced technology attachment (ATA), serial ATA (SATA),advanced technology attachment packet interface (ATAPI), serial storagearchitecture (SSA), integrated drive electronics (IDE), or anycombination thereof. The network coupled to network interface 160 orvarious components associated therewith may be implemented usinghardware, software, or any combination thereof.

In information handling system 100, I/O subsystem 140 may comprise asystem, device, or apparatus generally operable to receive and transmitdata to or from or within information handling system 100. I/O subsystem140 may represent, for example, a variety of communication interfaces,graphics interfaces, video interfaces, user input interfaces, andperipheral interfaces. In various embodiments, I/O subsystem 140 may beused to support various peripheral devices, such as a touch panel, adisplay adapter, a keyboard, an accelerometer, a touch pad, a gyroscope,or a camera, among other examples. In some implementations, I/Osubsystem 140 may support so-called ‘plug and play’ connectivity toexternal devices, in which the external devices may be added or removedwhile portable information handling system 100 is operating.

Also shown in FIG. 1 is embedded controller (EC) 180, which may includeEC processor 182 as a second processor included within portableinformation handling system 100 for certain management tasks, includingsupporting communication and providing various functionality withrespect to internal BMU 170-1. Thus, EC processor 182 may have access toEC memory 184, which may store EC firmware 186, representinginstructions executable by EC processor 182.

In some embodiments, EC firmware 186 may include pre-boot instructionsexecutable by EC processor 182. For example, EC firmware 186 may beoperable to prepare information handling system 100 to boot byactivating various hardware components in preparation of launching anoperating system for execution. Accordingly, in some embodiments, ECfirmware 186 may include a basic input/output system (BIOS). In certainembodiments, EC firmware 186 includes a Unified Extensible FirmwareInterface (UEFI) according to a specification promulgated by the UEFIForum (uefi.org). Embedded controller 180 may execute EC firmware 186 onEC processor 182 even when other components in information handlingsystem 100 are inoperable or are powered down. Furthermore, EC firmware186 may be in control of EC communication interface(s) 188, which mayrepresent one or more input/output interfaces or signals that embeddedcontroller 180 can use to communicate with other elements of informationhandling system 100, such as processor subsystem 120 or I/O subsystem140, among others.

Also shown within embedded controller 180 is power control 148, whichmay be responsible for managing electrical power connections betweenpower storage adapter 172, internal BMU 170-1, and to portableinformation handling system 100. In some embodiments, power control 148may be implemented as a separate controller external to embeddedcontroller 180. For example, when variable power bus 142 supplieselectrical power to portable information handling system 100, powercontrol 148 may determine whether the electrical power is used to chargeinternal battery 171 or to directly power portable information handlingsystem 100. Power control 148 may also manage so-called ‘soft start up’of portable information handling system 100, such as when portableinformation handling system 100 awakes from a low power state, such assleep mode, by determining a source of power during the low power stateand managing operation of portable information handling system 100during the low power state. Power control 148 may accordingly routeelectrical power and communicate with internal BMU 170-1 via DC powerand control 144, which may represent suitable connections betweenembedded controller 180 and internal BMU 170-1, for example. It is notedthat in some embodiments, at least certain portions of power control 148may be implemented using EC firmware 186, such as specialized executableinstructions for power management and control.

In particular embodiments, embedded controller 180 may support avariable power bus 142, which may represent a data bus that also carriesand distributes electrical power to and from portable informationhandling system 100. In various embodiments, variable power bus 142supports different levels of direct-current (DC) power that may beprovided to certain peripherals connected to I/O subsystem 140. Inparticular embodiments, variable power bus 142 may be used to receive DCpower from an external source, such as a power storage adapter 172. Forexample, the DC power received from the external source may be routedvia DC power connection 144 to internal BMU 170-1 for purposes ofcharging internal battery 171 or otherwise powering portable informationhandling system 100.

In certain embodiments, variable power bus 142 is implemented accordingto an industry standard, such as a Universal Serial Bus (USB), which isdeveloped and supported by the USB Implementers Forum, Inc. (USB IF,www.usb.org). In particular, variable power bus 142 may be implementedas a USB Type-C bus that may support different USB devices, such as USBType-C devices with USB Type-C connectors. Accordingly, variable powerbus 142 may support device detection, interface configuration,communication, and power delivery mechanisms according to the USB Type-Cstandard. The USB Type-C connector system allows the transport of dataand electrical power (in the form of DC power) between various USBdevices that are connected using USB Type-C ports and USB Type-Cconnectors. A USB device may be an information handling system, aperipheral device, a power device, among other types of USB devices, andmay support more than one USB standard or generation, such as USB 1.0,USB 2.0, USB 3.0, USB 3.1, or other versions. Furthermore, USB devicesmay also support one or more types of physical USB ports andcorresponding connectors (i.e., receptacles and plugs), such as Type-A,Type-A SuperSpeed, Type-B, Type-B SuperSpeed, Mini-A, Mini-B, Micro-A,Micro-B, Micro-B SuperSpeed, and Type-C (also referred to as USB Type-Cherein), among other variants. In one example, USB 3.1 Type-C cables mayprovide electronic functionality using an integrated semiconductordevice with an identification function based on a configuration datachannel and vendor-defined messages (VDMs) from a USB Power Deliveryspecification published by USB IF(http://www.usb.org/developers/powerdelivery/). Examples of source powerrules governed by the USB Power Delivery Specification, revision 2.0,version 1.2 are given in Table 1 below.

TABLE 1 USB Power Delivery revision 2.0, version 1.2 source power rules.Source Output Current [A] Current [A] Current [A] Current [A] Power [W]at +5 V DC at +9 V DC at +15 V DC at +20 V DC 0.5 to 15  0.1 to 3.0 nonenone none 15 to 27 3.0 (15 W limit) 1.7 to 3.0 none none 27 to 45 3.0(15 W limit) 3.0 (27 W limit) 1.8 to 3.0 none 45 to 60 3.0 (15 W limit)3.0 (27 W limit) 3.0 (45 W limit) 2.25 to 3.0  60 to 100 3.0 (15 Wlimit) 3.0 (27 W limit) 3.0 (45 W limit)  3.0 to 5.0As shown in Table 1, USB Power Delivery defines four standardizedvoltage levels (+5V DC, +9V DC, +15V DC, and +20V DC), while powersupplies may provide electrical power from 0.5 W to 100 W.

A USB device, such as a USB Type-C device, may provide multiple powerports that can individually transfer power in either direction and mayaccordingly be able to operate as a power source device, a power sinkdevice, or both (dual-role power device). A USB device operating as adual-role power device may operate as a power source or a power sinkdepending on what kinds of other USB devices are connected. In addition,each of the multiple power ports provided by the USB device may be adual-role power port that is able to operate as either a power sourceport or a power sink port. For example, a USB Type-C bus, such asvariable power bus 142, may support power delivery from a power sourceport of a power source USB device to a power sink port of a power sinkUSB device, while simultaneously supporting bidirectional USB datatransport. The power source port of the power source USB device and thepower sink port of the power sink USB device form a power port pair.Each of the other power ports provided by the USB device may form otherpower port pairs of other USB dual-role power devices.

According to the USB Power Delivery Specification, USB Type-C devicesmay perform a negotiation process to negotiate and establish a powercontract for a particular power port pair that specifies a level of DCpower that is transferred using USB. For example, a USB Type-C devicemay negotiate a power contract with another USB device for a level of DCpower that is supported by a power port pair of both devices, where onepower port is a power source port of the USB Type-C device and the otherpower port is a power sink port of the other USB device. The powercontract for power delivery and consumption may represent an agreementreached between the power source device and the power sink device forthe power port pair. While operating in Power Delivery mode, the powercontract for the power port pair will generally remain in effect unlessaltered by a re-negotiation process, a USB soft reset, a USB hard reset,a removal of power by a power source, a failure of the power source, ora USB role swap (such as between power source and power sink devices),as specified in detail by USB IF. When a particular power contract is inplace, additional power contracts can be established between anotherpower port of the power source device and a power port of another powersink device.

According to the USB Power Delivery specification, the negotiationprocess may begin with the power source device detecting an attachmentof a USB device operating as a power sink to a power port of the powersource device. In response to the detection of the attachment at therespective USB ports, the power source device may communicate a set ofsupported capabilities including power levels, voltage levels, currentlevels, and direction of power flow of the power port of the powersource device by sending the set of supported capabilities to the powersink over the USB connection. In response to receiving the set ofsupported capabilities, the power sink device may request one of thecommunicated capabilities by sending a request message to the powersource device. In response to receiving the request message, the powersource device may accept the request by sending an accept message and byestablishing a power source output corresponding to the request. Thepower contract for the power port pair may be considered established andin effect when the power source device sends the accept message to thepower sink device, which ends the negotiation process. A re-negotiationprocess may occur in a similar manner when a power contract is alreadyin effect.

During the negotiation process, a power sink USB device that may beunable to fully operate at any of the communicated capabilities mayrequest a default capability but indicate that the power sink USB devicewould prefer another power level. In response to receiving the defaultcapability request, the power source device may accept the defaultcapability request by storing the power sink USB device's preferredpower level, sending an accept message, and by establishing a powersource output corresponding to the default capability request.

During the various negotiation processes described above for USB PowerDelivery, the negotiation may fail when a request is not accepted, andmay result in no power contract being established. For example, thepower sink USB device and the power source USB device may have timeoutsfor pending requests, or other communications, to a respectivecounterparty. When a counterparty does not respond within the timeout, apending request or other communication may fail. It is also noted thatin some embodiments, a power delivery contract for zero electrical powermay be established, such that no power is transferred but the power portpair remains connected over the USB connection.

As illustrated in FIG. 1, each of portable information handling system100 and power storage adapter 172 may include a battery management unit(BMU) 170 that controls operation of a respective battery. In particularimplementations, BMU 170 may be embedded within a respective batterywhose operation BMU 170 controls. For example, internal BMU 170-1 withinportable information handling system 100 may control operation of aninternal battery 171, while PSA BMU 170-2 within power storage adapter172 may control operation of a PSA battery 174. More specifically, BMU170-1 may monitor information associated with, and control chargingoperations of, internal battery 171, while BMU 170-2 may monitorinformation associated with, and control charging operations of, PSAbattery 174. In operation, each BMU 170 may control operation of arespective battery to enable sustained operation, such as by protectingthe battery. Protection of the battery by BMU 170 may comprisepreventing the battery from operating outside of safe operatingconditions, which may be defined in terms of certain allowable voltageand current ranges over which the battery can be expected to operatewithout causing self-damage. For example, the BMU 170 may modify variousparameters in order to prevent an over-current condition (whether in acharging or discharging mode), an over-voltage condition duringcharging, an under-voltage condition while discharging, or anover-temperature condition, among other potentially damaging conditions.

As used herein, “top-of-charge voltage” (or “TOC” voltage) refers to avoltage threshold used during a charge cycle of a battery to determine a100% charge level. It is noted that the top-of-charge voltage set on agiven battery may be lower than a “maximum charge voltage”, which mayspecify a maximum voltage that a given battery having a given batterychemistry can safely endure during charging without damage. As usedherein, the terms “state of charge”, “SOC”, or “charge level” refer toan actual charge level of a battery, from 0% to 100%, for example, basedon the currently applied top-of-charge voltage. The SOC may becorrelated to an actual voltage level of the battery, for example,depending on a particular battery chemistry.

In some embodiments, a battery (such as internal battery 171 or PSAbattery 174 illustrated in FIG. 1) may be considered to be dischargedwhen an SOC of the battery corresponds to an SOC that is below apredetermined threshold percentage or amount below the 100% charge levelgiven by the TOC voltage, such as below a 5% charge level in oneexample. A battery may be considered to be charged, i.e., at leastpartially charged, when the SOC for the battery corresponds to an SOCthat is above a first predetermined threshold percentage or amount belowthe 100% charge level given by the TOC voltage, such as above the 25%charge level in one example. A battery may be considered to be fullycharged when the SOC of the battery corresponds to an SOC that is abovea second predetermined threshold percentage or amount below the 100%charge level given by the TOC voltage, such as above the 95% chargelevel for example. A battery may be considered to be at least partiallydischarged when the SOC of the battery corresponds to an SOC that isbelow the 100% charge level. The parameters for specifying an SOCdescribed above are examples and may be modified using different valuesin different embodiments.

In various embodiments, a battery (such as internal battery 171 or PSAbattery 174 illustrated in FIG. 1) may include one or more cells havinga particular chemistry in a particular cell configuration. For example,in one embodiment, the battery may include four Lithium-ion cells in atwo parallel-two serial (2S-2P) configuration. In other embodiments, thebattery may include a different number of cells or may include multiplecells in a different configuration. For example, the battery may includethree or more cells in various configurations. In some embodiments, thebattery may include one or more cells based on any one of a variety ofLithium-ion electrochemistries, or one or more cells based a differentelectrochemistry than Lithium-ion.

As shown in FIG. 1, power storage adapter 172 may be designed toremovably couple to portable information handling system 100 usingvariable power bus 142. For example, variable power bus 142 may includepower connections for electrically coupling power storage adapter 172 toportable information handling system 100 as an external load on powerstorage adapter 172. Variable power bus 142 may also include acommunication link to enable power storage adapter 172 to communicatewith portable information handling system 100, such as via embeddedcontroller 180. For example, power storage adapter 172 may communicatebattery data collected locally at power storage adapter 172 to portableinformation handling system 100 over a communication link withinvariable power bus 142. In other embodiments, there may be acommunication link between power storage adapter 172 and portableinformation handling system 100 that is separate from variable power bus142 instead of, or in addition to, a communication link that is part ofvariable power bus 142. In some embodiments, a communication linkbetween power storage adapter 172 and portable information handlingsystem 100, or DC power and control 144, may operate in accordance witha System Management Bus (SMBus) protocol for sending and receiving data.As noted above, in particular embodiments, variable power bus 142 iscompatible with USB Type-C and may be implemented according to USBType-C and USB Power Delivery specifications promulgated by USB IF.

In various embodiments, each of internal battery 171 or PSA battery 174may include at least certain portions of a main power circuit acrosspositive and negative terminals, a current sensor, a voltage sensor, oneor more battery cells, a fuse, and a power switch (not shown). Thecurrent sensor may represent a shunt resistor, or other current sensingelement, over which a voltage that is directly proportional to thecurrent flowing through the main power circuit is measured. The batterycells may store and output electrical energy based on a givenelectrochemical composition internal to the battery cells. The voltagesensor may enable voltage measurement of individual battery cells, ormeasurement of an aggregate voltage for the battery including allbattery cells operating together. The temperature sensor may be locatedin proximity to the battery cells to provide an accurate indication of atemperature within the battery. The fuse may be a safety element forlimiting current flowing through the main power circuit. The powerswitch may be an electronically controlled switching element that closesor opens the main power circuit, and thereby allows the battery tooperate for charging or discharging.

In FIG. 1, each BMU 170 may include a charging unit (see FIG. 2,charging unit 246) that may control charging cycles for a battery andmay apply a TOC voltage as a threshold to determine when charging iscomplete as the battery voltage increases during charging. The TOCvoltage may be lower than or equal to the maximum charge voltage thatthe battery can physically sustain, in different embodiments. Dependingon the actual value for the TOC voltage, a given energy capacity may bestored using the battery. BMU 170 may also be enabled to obtain varioustypes of information associated with a battery and to make decisionsaccording to the obtained information. For example, each BMU 170 maymonitor various charging-related parameters or other operatingparameters received from one or more batteries, including parametersreceived from a local battery or parameters received from a remotebattery over variable power bus 142.

In some embodiments, parameters monitored by a BMU 170 may include acharging current, a voltage, and a temperature associated with abattery. More specifically, the parameters monitored by the BMU 170 mayinclude any or all of the cell configuration and chemistry of batterycells within the battery, the total voltage of the battery, the voltagesof individual battery cells, minimum or maximum cell voltages, theaverage temperature of the battery as a whole, the temperatures ofindividual battery cells, the SOC of the battery, the depth of dischargeof the battery, the current flowing into the battery, the currentflowing out of the battery, and any other measurement of the overallcondition of the battery, in various embodiments. In some embodiments,monitoring the SOC may include continuous or periodic monitoring ofbattery output current, voltage, or both. In some cases, Coulombcounting, in which the charge delivered or stored by a battery istracked, is used for battery monitoring. In some embodiments, a batterytemperature may be monitored through the use of periodic voltagemeasurements, a thermometer, or any other method to detect or correctfor variations in temperature. In some embodiments, at least some of theparameters monitored by BMU 170 may be used internally by BMU 170 forinternal battery management operations. In some embodiments, at leastsome of the parameters monitored by BMU 170 may be provided to anotherdevice, such as information associated with PSA battery 174 that isprovided to or obtained by PSA BMU 170-2 on power storage adapter 172,and which may be provided to portable information handling system 100over variable power bus 142.

In some embodiments, BMU 170 may calculate additional values, based onthe monitored battery parameters or other information obtained from abattery, for example, in order to make decisions related to the chargingand operation of the battery. For example, BMU 170 may calculate any orall of a charge current limit (CCL), a discharge current limit (DCL), atotal amount of energy delivered, an amount of energy delivered sincethe last charge, an amount of charge delivered or stored, a number ofcharging cycles, a total operating time, and an operating time since thelast charge. In some embodiments, BMU 170, or another component ofportable information handling system 100 or power storage adapter 172,may analyze and compare monitored parameter values to historic values orpredicted models relative to an SOC of the battery, and may calculatethe remaining battery life. Remaining battery life may refer to aduration or a fraction of a time period remaining that a battery maysafely provide electrical power, an amount or a fraction of a voltagedrop remaining over which a battery may safely provide electrical power,or an amount or fraction of a discharge capacity remaining that abattery may safely provide electrical power. Based on the obtained andcalculated values, BMU 170 may detect various alert conditionsassociated with a battery, conditions such as battery charge full,battery charge empty, battery charging, battery discharging, batteryover temperature, battery over current, other battery system statusconditions, or various combinations thereof. In some embodiments,information indicating an alert condition for PSA battery 174 that isdetected by PSA BMU 170-2 on power storage adapter 172 may be providedto portable information handling system 100 over variable power bus 142.

In various embodiments, BMU 170 may further include a DC boost converter(see FIG. 2, DC boost converter 248) that is capable of boosting thevoltage provided by the cells within a battery. The DC boost convertermay be externally controlled to provide a desired boost voltage outputfrom the battery, such as in response to a control signal or othertrigger condition. Because the internal output voltage of the batterymay be constrained by the particular battery electrochemistry used toimplement the cells, the DC boost converter may enable the battery tooutput a higher voltage, as desired. In some embodiments, the DC boostconverter may be a buck-boost type converter that can step up or stepdown an input DC voltage.

In some embodiments, embedded controller 180 may implement a voltagecontrol module that senses the current drawn by an electrical load andprovides a control signal to BMU 170-1 based on the current drawn by theelectrical load. For example, the voltage control module may beimplemented as executable code stored by EC memory 184, while theelectrical load may be information handling system 100, or portionsthereof. It may be advantageous, for example, to provide a highervoltage to the electrical load in order to minimize the power dissipatedby losses incurred in transmitting current from internal battery 171 tothe electrical load. In another embodiment, the voltage control modulemay provide control signals in response to a voltage set signal. Thevoltage set signal may instruct the voltage control module to controlBMU 170-1 to produce a particular voltage at the load. For example, theparticular voltage level may allow the load to operate in a desired modeof operation. In one embodiment, the particular voltage level indicatedby the voltage set signal may be higher than the voltage output by cellswithin a battery. BMU 170-1 may boost the voltage output by the cells tothe voltage indicated by the voltage set signal.

For example, in some embodiments, a battery (such as internal battery171 or PSA battery 174 illustrated in FIG. 1) may provide electricalpower to the information handling system 100 at an output voltagecontrolled by its respective BMU 170. In some cases, portableinformation handling system 100 may provide load state information tothe voltage control module. In some embodiments, the load stateinformation may be based on the operating mode of the load, or on adesired future operating mode of the load. The voltage control modulemay determine a voltage level based on the load state information, andmay provide voltage control information based on the determined voltagelevel to internal BMU 170-1 or PSA BMU 170-2. In one embodiment, voltagecontrol information provided to PSA BMU 170-2 may specify the outputvoltage level of power storage adapter 172. In another embodiment,voltage control information provided to PSA BMU 170-2 may indicate apreferred voltage range for the output voltage level of power storageadapter 172. In yet another embodiment, voltage control informationprovided to PSA BMU 170-2 may indicate that the output voltage level ofpower storage adapter 172 should be increased or should be decreased.

In certain embodiments, BMU 170 may include a processor and memory (notshown). The memory may store instructions executable by the processor toperform one or more of the methods described herein for obtaining andcalculating values related to the operation and charging of a batteryand for controlling the operation and charging of the battery. Thememory may also store data, obtained and calculated values, thresholds,and parameters related to the methods described herein.

In FIG. 1, power storage adapter 172 is shown receiving AC line power146 as an external power source. AC line power 146 may represent aconnection to line power, such as using a standard line power cable. Insome embodiments, AC line power 146 may be a removable connection, suchas a cable that plugs into line power in a wall socket, and plugs into acorresponding receptacle included with power storage adapter 172. Alsoincluded within power storage adapter 172 in FIG. 2 is AC-DC converter176. AC-DC converter 176 may receive alternating current (AC) from ACline power 146 and may output one or more DC voltages for supplyingelectrical power to other components in power storage adapter 172. Forexample, an output DC voltage from AC-DC converter 176 may be suppliedto PSA battery 174 for charging purposes. An output DC voltage fromAC-DC converter 176 may be supplied to a DC-DC converter 178, which maythen generate one or more other DC voltages. Also, an output DC voltagefrom AC-DC converter 176 may be directly supplied to variable power bus142, such as to fulfil a power contract, as described above. Additionaldetails of power storage adapter 172 are described below with respect toFIG. 2 and FIGS. 3A and 3B.

As will be described in further detail herein, power storage adapter 172may include a high efficiency architecture for power distribution.Specifically, power storage adapter 172 may include a 20V_AC bar that isused to directly supply electrical power externally via ports 230, aswell as supplying electrical power for internal purposes. In thismanner, power storage adapter 172 may eliminate a voltage regulator fora 20V output voltage, thereby reducing losses from the potential use ofthe 20V voltage regulator. Furthermore, the 20V_AC bar may supplyelectrical power to a DC boost converter that can boost an output of aPSA battery to provide 20V boost current that can be used to augment theoutput power supplied by power storage adapter 172 from an AC line powersource. A charging unit may be used to boost a charging voltage of thePSA battery in order to more efficiently charge the PSA battery. In someconfigurations, a battery voltage V_(BAT) may be used to directly supplyelectrical power via ports 230. The battery voltage V_(BAT) maygenerally be in the range of 5V-20V, and may have other ranges indifferent embodiments, such as a range of 10V-20V, 5V-15V, 12V-20V, or12V-16.8V in particular embodiments. Various features and advantages ofthe high efficiency architecture for power storage adapter 172 aredescribed in further detail herein.

Referring now to FIG. 2, selected elements of an embodiment of a system200 with portable information handling system 100 and power storageadapter 172 are shown. FIG. 2 illustrates further internal details ofpower storage adapter 172. It is noted that FIG. 2 is not drawn to scalebut is a schematic illustration. In various embodiments, power storageadapter 172 may be implemented using fewer or additional components thanillustrated in FIG. 2.

In FIG. 2, power storage adapter 172 is coupled to portable informationhandling system 100 via variable power bus (VPB) 142, as described abovewith respect to FIG. 1. Additionally, power storage adapter 172 is alsoexternally connected to AC line power 146, as described above withrespect to FIG. 1.

As shown in FIG. 2, power storage adapter 172 includes power sources250, a DC-DC converter 178, a VPB controller 240, and two ports 230, aswell as a PSA controller 221 comprising processor 220 and memory 224. Asshown, power sources 250 comprise an AC-DC converter 176, a PSA battery174, and a PSA BMU 170-2. In FIG. 2, PSA BMU 170-2 is shown including acharging unit 246 and a DC boost converter 248, while VPB controller 240is shown including a power distributor 242 and a data hub 244. In someembodiments, DC boost converter 248 may include buck-boost DC conversionfunctionality to step up or step down an input DC voltage. VBPcontroller 240 is depicted in FIG. 2 in an implementation with two ports230-1 and 230-2 that support variable power bus 142. As noted above,variable power bus 142 may be compatible with USB Type-C specificationspromulgated by USB IF. Accordingly, in particular embodiments, port230-1 may be a USB Type-C port. In different embodiments, port 230-1 mayalso be a USB Type-C port or another type of port, such as a USB Type-Aport, among others. Although two ports 230 are shown in the exampleembodiment of FIG. 2, it will be understood that power storage adapter172 may include fewer or more ports 230 in different embodiments.

As shown in FIG. 2, power storage adapter 172 includes PSA controller221, which may perform various actions and functions. In someembodiments, PSA controller 221 is implemented using a custom integratedcircuit, or a customizable integrated circuit, such as a fieldprogrammable gate array (FPGA). In the embodiment shown in FIG. 2, PSAcontroller 221 includes processor 220 and memory 224, which may storeexecutable instructions (such as executable code) that may be executedby processor 220, which has access to memory 224. Processor 220 istypically implemented as an integrated circuit, such as a microprocessoror microcontroller, and is enabled to execute instructions that causepower storage adapter 172 to perform the functions and operationsdescribed herein. For the purposes of this disclosure, memory 224 mayinclude non-transitory computer-readable media that stores data andinstructions for at least a period of time. Memory 224 may comprisepersistent and volatile media, fixed and removable media, and magneticand semiconductor media. Memory 224 may include, without limitation,storage media such as a direct access storage device (e.g., a hard diskdrive or floppy disk), a sequential access storage device (e.g., a tapedisk drive), compact disk (CD), random access memory (RAM), read-onlymemory (ROM), CD-ROM, digital versatile disc (DVD), electricallyerasable programmable read-only memory (EEPROM) or flash memory,non-transitory media, or various combinations of the foregoing. Memory224 is operable to store instructions, data, or both. Memory 224 maystore sets or sequences of instructions that may represent executablecomputer programs for implementing various functionality provided bypower storage adapter 172.

The functionality and implementation details of certain elements inpower storage adapter 172, such as AC-DC converter 176, PSA battery 174,PSA BMU 170-2, and DC-DC converter 178, are described above with respectto FIG. 1.

As shown, VPB controller 240 may include power distributor 242, whichmay represent various electronic components that enable distribution ofDC power with respect to variable power bus 142 via ports 230.Specifically, power distributor 242 may receive at least one DC powerinput from DC-DC converter 178. Power distributor 242 may route orswitch power connections to respective ports 230, for example, to enablefulfillment of a power contract, as described above. A power contractestablished by VPB controller 240, such as according to a USB PowerDelivery Specification, may govern the supply of DC power to portableinformation handling system 100 via port 230-1. VPB controller 240 mayalso establish another power contract to supply DC power to anotherdevice coupled to port 230-2. In some embodiments, VPB controller 240supplies DC power to both port 230-1 and port 230-2. Power distributor242 may supply different DC voltages for output power at different ports230. In particular embodiments, power distributor 242 supplies adifferent DC voltage to port 230-1 than to port 230-2.

In FIG. 2, data hub 244 may represent electronic functionality to managevarious VPB connections over variable power bus 142. Specifically, datahub 244 may control operation of power distributor 242 and may, in turn,be controlled by PSA controller 221, such as by executable code (notshown) stored in memory 224 and executed by processor 220. Additionally,data hub 244 may store state information for each respective port 230,such as USB state information. For example, data hub 244 may storeinformation associated with power contracts that power storage adapter172 has established or is in the process of negotiating. Accordingly,data hub 244 may store various information about different VPB devicesconnected to power storage adapter 172 via ports 230. As used herein,the phrase “power consuming device” may refer to any system, apparatus,or device that is designed and/or configured to consume the electricalpower provided by a battery when such power is available and/or undercertain conditions. For example, a portable information handling systemmay consume power for components such as one or more displays,processors, storage media, memory, or other components. A batteryproviding electrical power to a power consuming device may be internalor external to the power consuming device, in different embodimentsand/or at different times.

In the illustrated embodiment, charging unit 246 of BMU 170-2 may drawelectrical power from AC-DC converter 176, and may, in turn output acharging voltage and charging current suitable to charge the cells ofPSA battery 174. The charging voltage and the charging current demandsof the battery may be dependent on an electrochemistry or a cellconfiguration of the battery cells. The charging of the battery may belimited by the current supply capability of the DC source. In someembodiments, the DC source may be AC-DC converter 176. Once the batteryreaches 100% state of charge, BMU 170-2 may stop drawing current fromthe AC-DC converter 176. When a boost source of power is desired,charging unit 246 may also be enabled to supply electrical from PSAbattery 174, which is then boosted to a desired output voltage by DCboost converter 248 (see also FIGS. 3A and 3B).

In some embodiments, portable information handling system 100 maycommunicate with power storage adapter 172 to instruct PSA BMU 170-2 tocharge the battery cells of PSA battery 174. As previously noted, PSABMU 170-2 may send information to portable information handling system100, such as the cell configuration, the state of charge of the battery,or other information. Portable information handling system 100 maycommunicate with PSA BMU 170-2 using a system management bus (notshown), for example System Management Bus (SMBus) promulgated by SBSImplementers Forum (www.smbus.org), in some embodiments.

Referring now to FIG. 3A, a power storage adapter 300 is illustrated inparticular detail. Specifically, power storage adapter 300 is anembodiment of power storage adapter 172 shown in FIGS. 1 and 2 withparticular elements and components illustrated. It is noted that FIG. 3Ais not drawn to scale but is a schematic illustration. In variousembodiments, power storage adapter 300 may be implemented using fewer oradditional components than illustrated in FIG. 3A.

In FIG. 3A, AC-DC converter 176 receives AC line power 146 as a sourceof electrical energy. Among other functionality, AC-DC converter 176 maygenerate a regulated 20V output to a 20V_AC bar 328 that distributes the20V to various different components included in power storage adapter300. For example, AC-DC converter 176 may directly output regulated 20Vvia 20V_AC bar 328 to power distributor 242, which is shown included inVPB controller 240. As shown, power distributor 242 may be enabled todistribute electrical power to ports 230-1 and 230-2, which may be USBports in particular embodiments. For example, power distributor 242 mayinclude a cross connect switch, such as a matrix switch, among otherelements, to distribute various power inputs to ports 230. Inparticular, power distributor 242 may implement OR functionality toprovide a particular voltage output to one of ports 230-1 and 230-2, butnot both ports 230. Because power delivery at ports 230 to a portableinformation handling system or another power consuming device may begoverned by USB power delivery specifications, power storage adapter 300may be implemented to limit supply of a particular voltage to a singleone of ports 230 by refusing a request for a second supply of electricalpower at the same voltage as is already being supplied to one of ports230.

Although the OR functionality with respect to ports 230 may limit thepossible power supply configurations of power storage adapter 300, inpractice, because the power delivery capacity of power storage adapter300 is finite, typical usage scenarios with portable informationhandling systems and other power consuming devices may rarely beconstrained in actual practice for users of power storage adapter 300.For example, port 230-1 may be a USB Type-C port used to power a primaryportable information handling system by a user, such as a Dell laptopcomputer or another brand of laptop computer. Then, the user may connectanother power consuming device, such as a secondary portable informationhandling system that is a cellular telephone associated with the user,to port 230-2, which may be a USB Type-C or a USB Type-A port. Becausethe secondary portable information handling system may consume lesselectrical power than the primary information handling system, thesecondary portable information handling system may negotiate andestablish a USB power delivery contract for a lower power, and hence, ata lower voltage (see also Table 1) than the primary portable informationhandling system. Furthermore, because the primary portable informationhandling system may easily consume more than half of the electricalpower supplied by power storage adapter 300, power storage adapter 300may be constrained from simultaneously supplying two primary portableinformation handling systems because of the rated electrical powercapability of power storage adapter 300.

As a result of the OR functionality with respect to ports 230 and 20V_ACbar 328, power storage adapter 300 may be implemented with fewer voltageregulators than other typical implementations or designs, such as otherconventional USB Type-C power sources. As shown in FIG. 3A, powerstorage adapter 300 may implement three voltage regulators in DC-DCconverter 178, corresponding to supply voltages specified by USB Type-C.Specifically, power storage adapter 300 may include a voltage regulator(VR) +5V DC 320, a VR +9V DC 322, and a VR +15V DC 324, each of whichmay be used for regulating an output voltage at either port 230-1 or230-2. In conventional designs, each output port 230 is typicallyequipped with a set of VRs that are dedicated to the port. Because VRshave a power inefficiency of about 8-10%, the reduction in the number ofVRs used in power storage adapter 300 may be a significant contributionto high efficiency operation. Accordingly, a DC boost converter 248-1(included with PSA BMU 170-2) may provide a 5V output to VR +5V DC 320,a 9V output to VR +9V DC 322, and a 15V output to VR +15V DC 324. Powerdistributor 242 may then selectively route the electrical power toindividual ones of output ports 230. It is noted that ports 230 may bedifferent types of ports, such as different types of USB ports. Forexample, port 230-1 may be a USB Type-C port, while port 230-2 may be aUSB Type-A port.

Also in FIG. 3A, charging unit 246 may charge PSA battery 174 accordingto a charging curve (see also FIG. 4) and may receive 20V_AC bar 328 asa voltage source of power. As shown in further detail with respect toFIG. 4, charging unit 246 may be enabled to use a boost charging voltagethat incrementally boosts a charging voltage of PSA battery 174. The useof the boost charging voltage by charging unit 246 may occur, in certainembodiments, when both ports 230 are disconnected and are not used forsupplying power from power storage adapter 300. Additionally, chargingunit 246 may supply electrical power from PSA battery 174 to DC boostconverter 248-1, for example, when AC line power 146 is not connectedand PSA battery 174 has a sufficient state of charge to supplyelectrical power. Also shown in a VR internal 334, which may be used byDC boost converter 248-1 for internal purposes.

Referring now to FIG. 3B, a power storage adapter 301 is illustrated inparticular detail. Specifically, power storage adapter 301 is anembodiment of power storage adapter 172 shown in FIGS. 1 and 2 withparticular elements and components illustrated. It is noted that FIG. 3Bis not drawn to scale but is a schematic illustration. In variousembodiments, power storage adapter 301 may be implemented using fewer oradditional components than illustrated in FIG. 3B.

In FIG. 3B, power storage adapter 301 is similar to power storageadapter 300 described above with respect to FIG. 3A and may operate asdescribed above for power storage adapter 300. In FIG. 3B, power storageadapter 301 additionally shows a battery voltage V_(BAT) 330 that isoutput directly from PSA battery 174 to a DC buck/boost converter 248-2.

When AC line power 146 is not connected, V_(BAT) may be used from DCbuck/boost converter 248-2 to generate a 20V_BAT voltage 328-2 using aVR +20V DC 332 for distribution by power distributor 242.

When AC line power 146 is connected, power distributor 242 may receiveboth 20V_AC bar 328-1 and 20V_BAT voltage 328-2 as a secondary source ofboost electrical power, and may combine both sources of 20V electricalpower to supply a boosted amount of electrical power. The boosted amountof electrical power supplied in this manner may exceed a nominal powerrating for AC-DC converter 176, for example. While 20V_AC bar 328-1supplies electrical power that is sourced from AC power line 146, theboost electrical power (20V_BAT 328-2) may be added to 20V_AC bar 328-1as long as PSA battery 174 has sufficient SOC and AC line power 146 isconnected and providing electrical power.

Additionally, power distributor 242 may also directly receive V_(BAT)330 from PSA battery 174, for example, when a different supply voltagethan shown in Table 1 are supplied to one or more of PSA ports 230. Forexample, when portable information handling system 100 connected to PSAport 230-1 is enabled to receive V_(BAT) 330 as a supply voltage, PSAadapter 301 may directly supply V_(BAT) 330 as a source of electricalpower. In this manner, electrical power supplied by PSA battery 174 maybe output at a voltage that is more efficient for operation of PSAbattery 174 (as compared to the fixed voltages in Table 1), which may bedesirable for power efficient operation of power storage adapter 301,and of PSA battery 174. In particular, the direct supply of V_(BAT) 330at one of PSA ports 230 may occur when AC line power 146 is notconnected and PSA battery 174 is the source of electrical power suppliedby power storage adapter 301.

FIG. 4 illustrates a charging curve 400 for a battery, such as internalbattery 171 or PSA battery 174. Charging curve 400 is schematicallyillustrated and is not drawn to scale or perspective. Charging curve 400may be implemented by BMU 170, for example, using charging unit 246 (seeFIG. 2). Charging curve 400 depicts how a charging current 402 and acharging voltage 404 respond over time to various conditions.Specifically, at time 410, it is assumed that the battery is dischargedand is charged by supplying charging current 402 that is constant, givenby Imax, which is a maximum charging current. In the constant currentcharging regime between time 410 and time 412, charging voltage 404 mayincrease from a low value to a higher value as the SOC for the batteryincreases. At time 412, charging voltage 404 may approach a maximumvalue, given by Vmax, and may remain constant after time 412. At abouttime 412, meanwhile, charging current 402 may begin to decrease as theSOC for the battery increases at a lower rate. After time 412, in aconstant voltage charging regime, charging current 402 may taper offuntil at some point, the SOC approaches a maximum value, and no furthercharging occurs.

Also shown in FIG. 4 is a boost charging voltage 406. Specifically,charging unit 246 may apply boost charging voltage 406 to improve acharging efficiency, for example, by reducing an amount of electricalpower consumed during charging, as compared with supplying constantcharging voltage Vmax.

Referring now to FIG. 5, a state diagram 500 for an embodiment of apower storage adapter controller 221 is depicted. More specifically,state diagram 500 illustrates various transitions between a state inwhich no electrical power is supplied by power storage adapter 172 toinformation handling system 100, a state in which electrical powersupplied to information handling system 100 by power storage adapter 172is sourced from AC-DC converter 176, and a state in which electricalpower supplied to information handling system 100 by power storageadapter 172 is sourced from PSA battery 174. In the description of thestate transition trigger conditions that follow, the term “PSAconnected” refers to a condition in which power storage adapter 172 iscoupled to both an information handling system 100 (or other powerconsuming device) and to AC line power 146. The term “PSA temperature”may refer to a temperature value for the PSA as a whole or for the AC-DCconverter of the PSA.

In the example embodiment illustrated in FIG. 5, trigger conditions 512for causing a transition from state 502 (“no power supplied by PSA”) tostate 504 (“power supplied by AC-DC converter”) may include thefollowing:

trigger condition 512-1=(PSA connected)+(default source=AC-DC converter)

trigger condition 512-2=(PSA connected)+(PSA temperature<maximumthreshold)

trigger condition 512-3=(PSA connected)+(SOC of PSA battery<minimumthreshold)

Trigger conditions 514 for causing a transition from state 502 (“nopower supplied by PSA”) to state 506 (“power supplied by PSA battery”)may include the following:

trigger condition 514-1=(PSA connected)+(PSA temperature>maximumthreshold)+(SOC of PSA battery>minimum threshold)

trigger condition 514-2=(PSA connected)+(default source=PSAbattery)+(SOC of PSA battery>minimum threshold)

Trigger conditions 510 for causing a transition from state 504 (“powersupplied by AC-DC converter”) to state 506 (“power supplied by PSAbattery”) may include the following:

trigger condition 510-1=(PSA connected)+(AC-DC converter operating atmaximum power supply capacity)+(SOC of PSA battery>minimum threshold)

trigger condition 510-2=(PSA connected)+(AC-DC converter operatingtime>maximum threshold)+(SOC of PSA battery>minimum threshold)

trigger condition 510-3=(PSA connected)+(PSA temperature>maximumthreshold)+(SOC of PSA battery>minimum threshold)

Trigger conditions 508 for causing a transition from state 506 (“powersupplied by PSA battery”) to state 504 (“power supplied by AC-DCconverter”) may include the following:

trigger condition 508-1=(PSA connected)+(PSA temperature<maximumthreshold)

trigger condition 508-2=(PSA connected)+(SOC of PSA battery<minimumthreshold)

Trigger conditions 516-1 and 516-2 for causing a transition to state 502(“no power supplied by PSA”) from state 504 (“power supplied by AC-DCconverter”) or from state 506 (“power supplied by PSA battery”),respectively, may include the following:

trigger condition 516=(PSA is decoupled from information handlingsystem) OR (PSA received indication to cease supplying electrical powerto information handling system)

In other embodiments, more, fewer, or different conditions may triggertransitions between states 502, 504, and 506.

Referring now to FIG. 6, a flow chart of selected elements of anembodiment of method 600 for sourcing power from a battery or AC-DCconverter of a power storage adapter, as described herein, is depictedin flowchart form. Method 600 may be performed by a power storageadapter 172 (see FIGS. 1, 2, and 3), and in particular by PSA controller221, to supply electrical power to a power consuming device. In someembodiments, method 600 may be performed by the execution of programinstructions stored in memory 224 and executed by processor 220. Inother embodiments, method 600 may be performed by a hardware statemachine or another type of hardware control circuit within power storageadapter 172. It is noted that certain operations described in method 600may be optional or may be performed in a different order than the orderdepicted in FIG. 6, in different embodiments.

Method 600 may begin, at step 602, with an AC-DC converter of a powerstorage adapter being coupled to AC line power, and a power consumingdevice being coupled to the power storage adapter over a variable powerbus. In some embodiments, the variable power bus may include powerconnections for electrically coupling the power consuming device and thepower storage adapter to each other and a communication link forexchanging information between the power consuming device and the powerstorage adapter. For example, the PSA controller may utilize a universalserial bus (USB) power delivery protocol layer for communicating withand supplying power to the power consuming device over the variablepower bus through a PSA port and an internal port, each of which is aUSB Type-C port.

At step 604, method 600 may include the power storage adapter receivinga request to supply electrical power to the power consuming device at aparticular voltage. In some embodiments, the PSA controller may includecircuitry to establish a power delivery contract to supply electricalpower to the power consuming device at the particular voltage and toconfigure the power storage adapter to supply electrical power to thepower consuming device over the variable power bus at the particularoutput voltage, as described herein. The particular voltage may be oneof multiple output voltage levels at which power is supplied by powerdistribution circuitry (such as power distributor 242 illustrated inFIG. 2) within the power storage adapter, as described herein.

At step 606, method 600 may include determining, based on an operatingparameter of the power storage adapter, one of an output of the AC-DCconverter or an output of a battery within the power storage adapter asa selected source for supplying electrical power to the power consumingdevice. For example, as illustrated in FIG. 5 and described above, thedetermination of the selected source may be dependent on the temperatureof the power storage adapter, the state of charge of the PSA battery,the amount of electrical power being supplied by the AC-DC converter, orthe amount of time that the AC-DC converter has been supplyingelectrical power to the information handling system, in differentembodiments.

At step 608, the method may include causing the power distributioncircuitry within the power storage adapter to supply electrical powerfrom the selected source to the power consuming device over the variablepower bus at the particular voltage. For example, circuitry within apower distributor of the power storage adapter may supply the combinedoutput power through a PSA port to an internal port of the powerconsuming device, each of which may be a USB Type-C port.

Referring now to FIG. 7, a flow chart of selected elements of anembodiment of method 700 for determining a selected source of power in apower storage adapter, as described herein, is depicted in flowchartform. Method 700 may be performed by a power storage adapter 172 (seeFIGS. 1, 2, and 3), and in particular by PSA controller 221, to supplyelectrical power to a power consuming device. In some embodiments,method 700 may be performed by the execution of program instructionsstored in memory 224 and executed by processor 220. In otherembodiments, method 700 may be performed by a hardware state machine oranother type of hardware control circuit within power storage adapter172. It is noted that certain operations described in method 700 may beoptional or may be performed in a different order than the orderdepicted in FIG. 7, in different embodiments.

Method 700 may begin, at step 702, with a power storage adapterreceiving a request to supply electrical power to a power consumingdevice at a particular voltage. In some embodiments, the power consumingdevice may be coupled to the power storage adapter over a variable powerbus that includes power connections for electrically coupling the powerconsuming device and the power storage adapter to each other and acommunication link for exchanging information between the powerconsuming device and the power storage adapter. The request to supplyelectrical power may be received over the communication link. Forexample, a PSA controller may utilize a universal serial bus (USB) powerdelivery protocol layer for communicating with and supplying power tothe power consuming device over the variable power bus through a PSAport and an internal port, each of which is a USB Type-C port. In someembodiments, the PSA controller may include circuitry to establish apower delivery contract to supply electrical power to the powerconsuming device at a particular voltage and to configure the powerstorage adapter to supply electrical power to the power consuming deviceat the particular voltage over the variable power bus.

At step 704, the method may include obtaining the values of one or morePSA operating parameters, at least some of which may indicate conditionson which the determination of a selected source of electrical power isdependent. For example, the PSA controller may obtain parameter valuesfrom any of a variety of sensors, including a current sensor, a voltagesensor, a temperature sensor, or another type of sensor that provides ameasurement value from which the temperature of the power storageadapter can be calculated. The PSA controller may also obtain, from aPSA battery management unit or from the PSA battery itself, ameasurement value representing the state of charge of the PSA battery.

If, at step 706, the battery is sufficiently charged to supply therequested electrical power, method 700 may proceed to step 710.Otherwise, method 700 may proceed to step 708. At step 710, the methodmay include determining that the AC-DC converter is the selected sourcefor supplying electrical power to the power consuming device.

If, at step 708, a PSA temperature value (e.g., a temperature value forthe PSA AC-DC converter) obtained by a sensor (or calculated based on ameasurement value obtained by another sensor) exceeds a maximumtemperature threshold, method 700 may proceed to step 714. Otherwise,method 700 may proceed to step 712. If, at step 712, the AC-DC converteris found to be sourcing power at its maximum power supply capacity, orabove a predetermined threshold amount below its maximum power supplycapacity, method 700 may proceed to step 714. Otherwise, method 700 mayproceed to step 716.

If, at step 716, the AC-DC converter is found to have been sourcingpower for an amount of time that exceeds a maximum threshold amount oftime for supplying power, method 700 may proceed to step 714. Otherwise,method 700 may proceed to step 718. At step 714, the method may includedetermining that the PSA battery is the selected source for supplyingelectrical power to the power consuming device.

At step 718, method 700 may include determining that the AC-DC converteris the selected source for supplying electrical power to the device.After determining, at step 710 or step 714, the selected source forsupplying electrical power to the power consuming device, method 700 mayreturn to step 706 in order to continue monitoring the operatingparameters and condition of the power storage adapter and changing theselected source of power as needed.

As disclosed herein, an external power storage adapter (PSA) may supplyelectrical power to a portable information handling system or otherpower consuming device. The power storage adapter may include an AC-DCconverter, a battery, and intelligent power management functionality. APSA controller may determine whether electrical power supplied by thepower storage adapter should be sourced from the AC-DC converter or fromthe battery based on various operating parameters of the power storageadapter, such the temperature of the power storage adapter, the state ofcharge of the battery, the amount of electrical power being supplied bythe AC-DC converter, or the amount of time that the AC-DC converter hasbeen supplying electrical power. The power storage adapter may outputpower to a port of the portable information handling system, such as aUSB Type-C port, over a variable power bus.

The above disclosed subject matter is to be considered illustrative, andnot restrictive, and the appended claims are intended to cover all suchmodifications, enhancements, and other embodiments which fall within thetrue spirit and scope of the present disclosure. Thus, to the maximumextent allowed by law, the scope of the present disclosure is to bedetermined by the broadest permissible interpretation of the followingclaims and their equivalents, and shall not be restricted or limited bythe foregoing detailed description.

What is claimed is:
 1. A power storage adapter (PSA), comprising: a portfor coupling the power storage adapter to a variable power bus; abattery; an AC-DC converter; power distribution circuitry to supplyelectrical power from the power storage adapter at a plurality of outputvoltage levels; and a PSA controller, wherein the PSA controllercomprises circuitry to: when the AC-DC converter is coupled to AC linepower and a power consuming device is coupled to the power storageadapter over the variable power bus through the port, and responsive toa request for the power storage adapter to supply electrical power tothe power consuming device at a particular voltage: determine, based onan operating parameter of the power storage adapter, one of an output ofthe AC-DC converter or an output of the battery as a selected source forsupplying electrical power to the power consuming device; and cause thepower distribution circuitry to supply electrical power from theselected source to the power consuming device over the variable powerbus at the particular voltage; wherein the particular voltage is one ofthe plurality of output voltage levels.
 2. The power storage adapter ofclaim 1, wherein the power consuming device is an information handlingsystem comprising an internal battery.
 3. The power storage adapter ofclaim 1, wherein: the power storage adapter further comprises a sensor;and the operating parameter is dependent on a measurement value obtainedby the sensor.
 4. The power storage adapter of claim 1, wherein todetermine the selected source, the PSA controller circuitry is furtherto: determine that a state of charge of the battery is greater than athreshold state of charge for supplying electrical power to the powerconsuming device at the particular voltage; and responsive todetermining that the state of charge of the battery is greater than thethreshold state of charge: determine that the selected source forsupplying electrical power to the power consuming device is to bechanged from an output of the AC-DC converter to an output of thebattery, dependent on at least one of: a determination that atemperature of the power storage adapter is greater than a thresholdtemperature for sourcing electrical power from the AC-DC converter; apercentage of a maximum power supply capacity of the AC-DC converter atwhich the AC-DC converter is currently operating; and an amount of timethat the AC-DC converter has been operating to supply electrical powerto the power consuming device.
 5. The power storage adapter of claim 1,wherein: to determine the selected source, the PSA controller circuitryis further to determine that the selected source for supplyingelectrical power to the power consuming device is to be changed from anoutput of the battery to an output of the AC-DC converter, dependent onat least one of: a determination that a state of charge of the batteryis less than or equal to a threshold state of charge for supplyingelectrical power to the power consuming device at the particularvoltage; and a determination that a temperature of the power storageadapter is less than or equal to a threshold temperature for sourcingelectrical power from the AC-DC converter.
 6. The power storage adapterof claim 1, wherein: the PSA controller utilizes a universal serial bus(USB) power delivery protocol layer for communicating with and supplyingelectrical power to the power consuming device over the variable powerbus; the port is a USB Type-C port; and the PSA controller furthercomprises circuitry to: establish a power delivery contract to supplyelectrical power to the power consuming device at the particularvoltage.
 7. The power storage adapter of claim 1, wherein: the AC-DCconverter is a default source for supplying electrical power to thepower consuming device when the AC-DC converter is coupled to AC linepower and the power consuming device is coupled to the power storageadapter over the variable power bus through the port; and to determinethe selected source, the PSA controller circuitry is further to:override the default source to determine that an output of the batteryis the selected source for supplying electrical power to the powerconsuming device.
 8. The power storage adapter of claim 1, wherein thePSA controller circuitry comprises: a processor; and a memory storingprogram instructions that when executed by the processor cause theprocessor to perform: the determining of the selected source; andgenerating one or more control signals to cause the power distributioncircuitry to supply electrical power from the selected source to thepower consuming device over the variable power bus at the particularvoltage.
 9. The power storage adapter of claim 1, wherein: the powerstorage adapter further comprises a DC-DC converter comprising circuitryto boost an initial output voltage of the battery to the particularvoltage to generate a boosted output voltage at which electrical poweris supplied to the power consuming device over the variable power bus.10. A method for supplying power to a power consuming device,comprising: when an AC-DC converter of a power storage adapter (PSA) iscoupled to AC line power and a power consuming device is coupled to thepower storage adapter over a variable power bus, and responsive toreceiving a request for the power storage adapter to supply electricalpower to the power consuming device at a particular voltage:determining, based on an operating parameter of the power storageadapter, one of an output of the AC-DC converter or an output of abattery within the power storage adapter as a selected source forsupplying electrical power to the power consuming device; and causingpower distribution circuitry within the power storage adapter to supplyelectrical power from the selected source to the power consuming deviceover the variable power bus at the particular voltage; wherein theparticular voltage is one of a plurality of output voltage levels atwhich electrical power is supplied by the power distribution circuitrywithin the power storage adapter.
 11. The method of claim 10, whereinthe power consuming device is an information handling system comprisingan internal battery.
 12. The method of claim 10, wherein the operatingparameter is dependent on a measurement value obtained by a sensorwithin the power storage adapter.
 13. The method of claim 10, whereindetermining the selected source comprises: determining that a state ofcharge of the battery is greater than a threshold state of charge forsupplying electrical power to the power consuming device at theparticular voltage; and responsive to determining that the state ofcharge of the battery is greater than the threshold state of charge:determining that the selected source for supplying electrical power tothe power consuming device is to be changed from an output of the AC-DCconverter to an output of the battery, dependent on at least one of: adetermination that a temperature of the power storage adapter is greaterthan a threshold temperature for sourcing electrical power from theAC-DC converter; a percentage of a maximum power supply capacity of theAC-DC converter at which the AC-DC converter is currently operating; andan amount of time that the AC-DC converter has been operating to supplyelectrical power to the power consuming device.
 14. The method of claim10, wherein determining the selected source comprises: determining thatthe selected source for supplying electrical power to the powerconsuming device is to be changed from an output of the battery to anoutput of the AC-DC converter, dependent on at least one of: adetermination that a state of charge of the battery is less than orequal to a threshold state of charge for supplying electrical power tothe power consuming device at the particular voltage; and adetermination that a temperature of the power storage adapter is lessthan or equal to a threshold temperature for sourcing electrical powerfrom the AC-DC converter.
 15. The method of claim 10, wherein: the powerstorage adapter utilizes a universal serial bus (USB) power deliveryprotocol layer for communicating with and supplying electrical power tothe power consuming device over the variable power bus through a USBType-C port of the power storage adapter; and the method furthercomprises: establishing a power delivery contract to supply electricalpower to the power consuming device at the particular voltage.
 16. Themethod of claim 10, wherein: the AC-DC converter is a default source forsupplying electrical power to the power consuming device when the AC-DCconverter is coupled to AC line power and the power consuming device iscoupled to the power storage adapter over the variable power bus throughthe port; and determining the selected source comprises: overriding thedefault source to determine that an output of the battery is theselected source for supplying electrical power to the power consumingdevice.
 17. The method of claim 10, wherein causing power distributioncircuitry within the power storage adapter to supply electrical powerfrom the selected source to the power consuming device over the variablepower bus at the particular voltage comprises: boosting an initialoutput voltage of the battery to the particular voltage to generate aboosted output voltage at which electrical power is supplied to thepower consuming device over the variable power bus.
 18. A system,comprising: an information handling system including an internal portfor coupling the information handling system to a variable power bus;and a power storage adapter (PSA) comprising: a PSA port for couplingthe power storage adapter to the information handling system over thevariable power bus; a battery; an AC-DC converter; power distributioncircuitry to supply electrical power from the power storage adapter at aplurality of output voltage levels; and a PSA controller, wherein thePSA controller comprises circuitry to: when the AC-DC converter iscoupled to AC line power and the information handling system is coupledto the power storage adapter over the variable power bus through theport, and responsive to a request for the power storage adapter tosupply electrical power to the information handling system at aparticular voltage: determine, based on an operating parameter of thepower storage adapter, one of an output of the AC-DC converter or anoutput of the battery as a selected source for supplying electricalpower to the information handling system; and cause the powerdistribution circuitry to supply electrical power from the selectedsource to the information handling system over the variable power bus atthe particular voltage; wherein the particular voltage is one of theplurality of output voltage levels.
 19. The system of claim 18, whereinto determine the selected source, the PSA controller circuitry isfurther to: determine that a state of charge of the battery is greaterthan a threshold state of charge for supplying electrical power to theinformation handling system at the particular voltage; and responsive todetermining that the state of charge of the battery is greater than thethreshold state of charge: determine that the selected source forsupplying electrical power to the information handling system is to bechanged from an output of the AC-DC converter to an output of thebattery, dependent on at least one of: a determination that atemperature of the power storage adapter is greater than a thresholdtemperature for sourcing electrical power from the AC-DC converter; apercentage of a maximum power supply capacity of the AC-DC converter atwhich the AC-DC converter is currently operating; and an amount of timethat the AC-DC converter has been operating to supply electrical powerto the information handling system.
 20. The system claim 18, wherein: todetermine the selected source, the PSA controller circuitry is furtherto determine that the selected source for supplying electrical power tothe information handling system is to be changed from an output of thebattery to an output of the AC-DC converter, dependent on at least oneof: a determination that a state of charge of the battery is less thanor equal to a threshold state of charge for supplying electrical powerto the information handling system at the particular voltage; and adetermination that a temperature of the power storage adapter is lessthan or equal to a threshold temperature for sourcing electrical powerfrom the AC-DC converter.